121121111 has 4 divisors (see below), whose sum is σ = 122253192. Its totient is φ = 119989032.

The previous prime is 121121083. The next prime is 121121113. The reversal of 121121111 is 111121121.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-121121111 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 121121092 and 121121101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121121113) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 565880 + ... + 566093.

It is an arithmetic number, because the mean of its divisors is an integer number (30563298).

Almost surely, 2^121121111 is an apocalyptic number.

121121111 is a deficient number, since it is larger than the sum of its proper divisors (1132081).

121121111 is a wasteful number, since it uses less digits than its factorization.

121121111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1132080.

The product of its digits is 4, while the sum is 11.

The square root of 121121111 is about 11005.5036686196. The cubic root of 121121111 is about 494.7737101235.

Adding to 121121111 its reverse (111121121), we get a palindrome (232242232).

It can be divided in two parts, 121121 and 111, that multiplied together give a palindrome (13444431).

The spelling of 121121111 in words is "one hundred twenty-one million, one hundred twenty-one thousand, one hundred eleven".